Quinetum is a cordial from Hendrick’s Gin. Do not feel bad if you have never heard of it. That is kind of the idea. Quinetum is sold exclusively to a few bars around the country. And Hendrick’s is not the only brand making a pitch to the cocktail cognoscenti. Tanqueray Gin reintroduced its Malacca version last year, marketed nearly exclusively to bars, and Absolut has its Absolut Craft, a collection designed for bartenders.

‘‘Everybody likes to feel like the thing that’s sitting in front of them that they just paid money for is special,” said Justin Burrow, proprietor of Captain Foxheart’s Bad News Bar & Spirit Lodge in Houston, which has Tanqueray’s limited production Malacca gin in the bar.

‘‘If you can tell them that they’re drinking something that maybe only 20 percent of the drinking population is getting to try, that adds value in the eyes of the consumer,” he says. ‘‘It makes them happy.”

Malacca, based on an old recipe by company founder Charles Tanqueray, was first introduced in the ’90s but was dropped. But bartenders, including Burrow, began asking for a rerelease. ‘‘It made the best Tom Collins. It did things that the London Dry gins wouldn’t do,” says Burrow.

A batch of 100,000 bottles was made and most were earmarked for bartenders.

Hendrick’s Quinetum, meanwhile, is available at about two dozen bars around the country. And at Rickhouse, you need to know to ask for it. The cordial, released this year, was created by Hendrick’s Gin master distiller Lesley Gracie, who was inspired by the work of Thomas Whiffen, a mathematician and chemist who promoted the use of quinine in the 19th century.

Only 4,000 bottles were made in the first batch, with 2,400 going to the United States. The cordial, 4 percent alcohol by volume, contains cinchona succirubra bark (the source of natural quinine), orange blossom, wormwood, and holy thistle, as well as lavender and orange distillates.

Drinking a limited edition liquor means that you cannot, in most cases, try this at home. But cocktail connoisseur Gary Regan, better known as ‘‘gazregan” and author of ‘‘The Joy of Mixology,” is fine with that. ‘‘I like the idea of sipping something that I’ll never be able to sip again. The limited edition part of this equation, for me I find that it’s just romantic.”